Static mechanical equipment, comprising pressure vessels, process piping, heat exchangers, storage tanks, and pressure relief systems, represents the largest share of hydrocarbon-containing inventory on offshore installations, yet it has historically received less structured maintenance attention than rotating machinery. Classical Reliability-Centered Maintenance (RCM) was developed around functional failures that announce themselves through measurable performance loss, a pattern typical of pumps, compressors, and turbines. Static equipment fails differently: degradation is slow, largely invisible, driven by corrosion and cracking mechanisms, and its first evident failure is often a loss of containment with severe safety and environmental consequences. This paper develops an RCM concept adapted to static mechanical equipment in offshore oil and gas operations. The concept retains the seven-question logic of SAE JA1011 but integrates Risk-Based Inspection (RBI) per API RP 580 and 581 as the principal on-condition task engine, adopts the consequence classification framework of NORSOK Z-008, and uses ISO 14224 taxonomies for failure data. A structured methodology is presented covering system boundary definition, functional analysis, failure mode, effects and criticality analysis (FMECA) oriented toward degradation mechanisms, task selection logic, and interval determination based on remaining-life and probability-of-failure models. The paper argues that a merged RCM-RBI framework produces a defensible, auditable, and cost-effective integrity management program that neither methodology achieves alone, and identifies data quality, organizational integration, and living-program governance as the decisive success factors for offshore implementation.